Energy storage device

Abstract

An energy storage device includes: an electrode having a composite layer formed by applying a composite directly or indirectly onto a substrate and a non-applied portion, onto which the composite is not applied; and a separator layered on the electrode to face the composite layer. Here, a drawn area is formed in at least. a part of the non-applied portion, and an intermediate layer is interposed at least between the drawn area and the composite layer.

What is claimed is: 
     
         1 . An energy storage device comprising:
 an electrode including a composite layer formed by applying a composite directly or indirectly onto a substrate and a non-applied portion, onto which the composite is not applied; and   a separator layered on the electrode to face the composite layer,   wherein a drawn area is formed in at least a part of the non-applied portion, and. an intermediate layer is interposed at least between the drawn. area and the composite layer.   
     
     
         2 . The energy storage device according to  claim 1 , wherein the intermediate layer includes an exposed portion that singly exists at least between the drawn area and the composite layer, and a non-exposed portion that exists under the composite layer. 
     
     
         3 . The energy storage device according to  claim 2 , wherein in the intermediate layer, a layer thickness D 1  at the exposed portion is set to be greater than a layer thickness D 2  at the non-exposed portion, and in the composite layer, an edge on a side facing the intermediate layer is located lower than the height of the surface of the exposed portion. 
     
     
         4 . The energy storage device according to  claim 3 , wherein the layer thickness D 2  at the non-exposed portion is set to 30% to 80% of the layer thickness D 1  at the exposed portion. 
     
     
         5 . The energy storage device according to  claim 1 , wherein in the intermediate layer, a projection width S 1  from the composite layer toward the non-applied portion is set to 0.5 mm to 2.5 mm. 
     
     
         6 . The energy storage device according to  claim 5 , wherein the projection width S 1  is set to 15% to 85% of a width S 2  from an end of the drawn area to an end of the composite layer. 
     
     
         7 . The energy storage device according to  claim 1 , wherein a peeling-off strength of the intermediate layer with respect to the substrate is greater than a peeling-off strength of the composite layer with respect to the intermediate layer. 
     
     
         8 . The energy storage device according to  claim 1 , wherein the peeling-off strength of the intermediate layer with respect to the substrate is 200 gf/cm or higher. 
     
     
         9 . The energy storage device according to  claim 1 , wherein the intermediate layer is a buffer that alleviates a stress transmitted from the drawn area. 
     
     
         10 . The energy storage device according to  claim 1 , wherein the intermediate layer includes an insulating exposed portion that exists only between the drawn area and the composite layer. 
     
     
         11 . The energy storage device according to  claim 1 , wherein the separator is a bonding separator that is bonded to the electrode. 
     
     
         12 . The energy storage device according to  claim 1 , wherein the electrode is an electrode coated with an insulating layer.